The support of machinery presents problems especially when the machinery has parts which operate with impacts or which oscillate to produce shocks and vibrations in the frame structure of the machinery. Such problems are of increased magnitude when it is desired to support the machinery on elevated floors and when the attempted solution is to fixedly secure the frame of the machinery to the floor because the resulting transmission of shocks and vibrations to the floor can cause damage thereto and to the supporting structure therefor.
Shock absorbers heretofore proposed for support of machinery have not been entirely satisfactory. In many cases, prior art arrangements have been unduly complicated and expensive and they have not been such as to obtain adequate isolation, particularly with respect to low frequency components and transient shocks of high amplitude. Prior art arrangements have also been unduly large in size and have been subject to failure of parts, especially in the case of constructions having exposed bellows and the like.
As an example of prior art disclosures, the Wendes U.S. Pat. No. 2,171,774 discloses a vibration damping device wherein a vibratory member extends into a channel defined by a C-shaped member with a plurality of resilient bodies between the vibratory member and the sides of the channel and with the vibration absorbing capacity of the bodies being described as being separately controllable.
The French et al U.S. Pat. No. 2,572,919 discloses a vibration damping system for optical observation instruments which includes springs, dashpots and an arrangement incorporating balls riding between cupped and inverted cupped parts to provide for lateral yield.
The Brown U.S. Pat. No. 2,605,066 discloses an air spring for heavy machinery using a bellows between a load plate and the upper end of a cylinder with a piston connected to the load plate being movable in liquid in the lower portion of the cylinder and with valves associated with the piston to meter liquid flow in response to downward movement and to allow free flow in response to upward movement.
The Williams U.S. Pat. No. 2,652,241 discloses a strut platform support in which a hydraulic fluid is contained between a pair of membranes to provide a hydraulic support and in which tiltable studs are provided to accommodate lateral movements.
The Keetch U.S. Pat. No. 3,146,979 discloses an arrangement in which balls are disposed between upwardly and downwardly facing circular concave raceways to translate horizontal forces into vertical forces with a ring member of a solid resilient materal being provided for absorbing vertical vibrations and shocks.
The May U.S. Pat. No. 3,281,101 discloses a levelable load mount for a machine susceptible to physical distortion when a multi-point support thereof fails to provide a proper levelling action. A plurality of pneumatic mounts are provided to which air is supplied through automatically controlled valving.
The Leary U.S. Pat. No. 3,425,652 discloses a vibration controlling mounting apparatus in which balls of elastomeric material are seated in semi-spherical sockets in the lower face of a mounting plate and are engaged in cups supported on shafts within annular collars of resilient material.
The Richard U.S. Pat. No. 3,730,463 discloses shock absorbing mountings in which a pair of ball races are disposed between the lower and upper horizontal planar faces of an apparatus support plate and upper and lower horizontal planar surfaces of a fixed support, for the purpose of providing low friction horizontal movement which is restrained only by a self-centering annular rubber body.
The Byers U.S. Pat. No. 3,771,270 discloses earthquake damage prevention devices using ball bearings to allow horizontal translational movements, the ball bearings being disposed between facing surfaces which are contoured to provide a centering action.